Files
ormar/docs/queries/aggregations.md
collerek 500625f0ec WIP - Pydantic v2 support (#1238)
* WIP

* WIP - make test_model_definition tests pass

* WIP - make test_model_methods pass

* WIP - make whole test suit at least run - failing 49/443 tests

* WIP fix part of the getting pydantic tests as types of fields are now kept in core schema and not on fieldsinfo

* WIP fix validation in update by creating individual fields validators, failing 36/443

* WIP fix __pydantic_extra__ in intializing model, fix test related to pydantic config checks, failing 32/442

* WIP - fix enum schema in model_json_schema, failing 31/442

* WIP - fix copying through model, fix setting pydantic fields on through, fix default config and inheriting from it, failing 26/442

* WIP fix tests checking pydantic schema, fix excluding parent fields, failing 21/442

* WIP some missed files

* WIP - fix validators inheritance and fix validators in generated pydantic, failing 17/442

* WIP - fix through models setting - only on reverse side of relation, but always on reverse side, failing 15/442

* WIP - fix through models setting - only on reverse side of relation, but always on reverse side, failing 15/442

* WIP - working on proper populating __dict__ for relations for new schema dumping, some work on openapi docs, failing 13/442

* WIP - remove property fields as pydantic has now computed_field on its own, failing 9/442

* WIP - fixes in docs, failing 8/442

* WIP - fix tests for largebinary schema, wrapped bytes fields fail in pydantic, will be fixed in pydantic-core, remaining is circural schema for related models, failing 6/442

* WIP - fix to pk only models in schemas

* Getting test suites to pass (#1249)

* wip, fixing tests

* iteration, fixing some more tests

* iteration, fixing some more tests

* adhere to comments

* adhere to comments

* remove unnecessary dict call, re-add getattribute for testing

* todo for reverse relationship

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* solve circular refs

* all tests pass 🎉

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* add lint and type check jobs

* reforat with ruff, fix jobs

* rename jobs

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* some small refactor in new base model, one sample test, change makefile

* small refactors to reduce complexity of methods

* temp add tests for prs against pydantic_v2

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* remove all references to construct, deprecate the method and update model_construct to be in line with pydantic

* deprecate dict and add model_dump, todo switch to model_dict in calls

* fix tests

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* change to union

* change to model_dump and model_dump_json from dict and json deprecated methods, deprecate them in ormar too

* finish switching dict() -> model_dump()

* finish switching json() -> model_dump_json()

* remove fully pydantic_only

* switch to extra for payment card, change missed json calls

* fix coverage - no more warnings internal

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* split model_construct into own and pydantic parts

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* fix benchmarks, add codspeed instead of pytest-benchmark, add action and gh workflow

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* change on push to pydantic_v2 to trigger first one

* Use lifespan function instead of event (#1259)

* check return types

* fix imports order, set warnings=False on json that passes the dict, fix unnecessary loop in one of the test

* remove references to model's meta as it's now ormar config, rename related methods too

* filter out pydantic serializer warnings

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* add migration guide

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* downgrade databases for now

* Change line numbers in documentation (#1265)

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* proofread and fix the docs for models

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* proofread and fix the docs for relations

* proofread and fix rest of the docs, add release notes for 0.20

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* cleanup old deps, uncomment docs publish on tag

* fix import reorder

---------

Co-authored-by: TouwaStar <30479449+TouwaStar@users.noreply.github.com>
Co-authored-by: Goran Mekić <meka@tilda.center>
2024-03-23 19:28:28 +01:00

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Markdown

# Aggregation functions
Currently 6 aggregation functions are supported.
* `count(distinct: bool = True) -> int`
* `exists() -> bool`
* `sum(columns) -> Any`
* `avg(columns) -> Any`
* `min(columns) -> Any`
* `max(columns) -> Any`
* `QuerysetProxy`
* `QuerysetProxy.count(distinct=True)` method
* `QuerysetProxy.exists()` method
* `QuerysetProxy.sum(columns)` method
* `QuerysetProxy.avg(columns)` method
* `QuerysetProxy.min(column)` method
* `QuerysetProxy.max(columns)` method
## count
`count(distinct: bool = True) -> int`
Returns number of rows matching the given criteria (i.e. applied with `filter` and `exclude`).
If `distinct` is `True` (the default), this will return the number of primary rows selected. If `False`,
the count will be the total number of rows returned
(including extra rows for `one-to-many` or `many-to-many` left `select_related` table joins).
`False` is the legacy (buggy) behavior for workflows that depend on it.
```python
class Book(ormar.Model):
ormar_config = ormar.OrmarConfig(
database=databases.Database(DATABASE_URL),
metadata=sqlalchemy.MetaData(),
tablename="book"
)
id: int = ormar.Integer(primary_key=True)
title: str = ormar.String(max_length=200)
author: str = ormar.String(max_length=100)
genre: str = ormar.String(
max_length=100,
default="Fiction",
choices=["Fiction", "Adventure", "Historic", "Fantasy"],
)
```
```python
# returns count of rows in db for Books model
no_of_books = await Book.objects.count()
```
## exists
`exists() -> bool`
Returns a bool value to confirm if there are rows matching the given criteria (applied with `filter` and `exclude`)
```python
class Book(ormar.Model):
ormar_config = ormar.OrmarConfig(
database=databases.Database(DATABASE_URL),
metadata=sqlalchemy.MetaData(),
tablename="book"
)
id: int = ormar.Integer(primary_key=True)
title: str = ormar.String(max_length=200)
author: str = ormar.String(max_length=100)
genre: str = ormar.String(
max_length=100,
default="Fiction",
choices=["Fiction", "Adventure", "Historic", "Fantasy"],
)
```
```python
# returns a boolean value if given row exists
has_sample = await Book.objects.filter(title='Sample').exists()
```
## sum
`sum(columns) -> Any`
Returns sum value of columns for rows matching the given criteria (applied with `filter` and `exclude` if set before).
You can pass one or many column names including related columns.
As of now each column passed is aggregated separately (so `sum(col1+col2)` is not possible,
you can have `sum(col1, col2)` and later add 2 returned sums in python)
You cannot `sum` non numeric columns.
If you aggregate on one column, the single value is directly returned as a result
If you aggregate on multiple columns a dictionary with column: result pairs is returned
Given models like follows
```Python
--8<-- "../docs_src/aggregations/docs001.py"
```
A sample usage might look like following
```python
author = await Author(name="Author 1").save()
await Book(title="Book 1", year=1920, ranking=3, author=author).save()
await Book(title="Book 2", year=1930, ranking=1, author=author).save()
await Book(title="Book 3", year=1923, ranking=5, author=author).save()
assert await Book.objects.sum("year") == 5773
result = await Book.objects.sum(["year", "ranking"])
assert result == dict(year=5773, ranking=9)
try:
# cannot sum string column
await Book.objects.sum("title")
except ormar.QueryDefinitionError:
pass
assert await Author.objects.select_related("books").sum("books__year") == 5773
result = await Author.objects.select_related("books").sum(
["books__year", "books__ranking"]
)
assert result == dict(books__year=5773, books__ranking=9)
assert (
await Author.objects.select_related("books")
.filter(books__year__lt=1925)
.sum("books__year")
== 3843
)
```
## avg
`avg(columns) -> Any`
Returns avg value of columns for rows matching the given criteria (applied with `filter` and `exclude` if set before).
You can pass one or many column names including related columns.
As of now each column passed is aggregated separately (so `sum(col1+col2)` is not possible,
you can have `sum(col1, col2)` and later add 2 returned sums in python)
You cannot `avg` non numeric columns.
If you aggregate on one column, the single value is directly returned as a result
If you aggregate on multiple columns a dictionary with column: result pairs is returned
```Python
--8<-- "../docs_src/aggregations/docs001.py"
```
A sample usage might look like following
```python
author = await Author(name="Author 1").save()
await Book(title="Book 1", year=1920, ranking=3, author=author).save()
await Book(title="Book 2", year=1930, ranking=1, author=author).save()
await Book(title="Book 3", year=1923, ranking=5, author=author).save()
assert round(float(await Book.objects.avg("year")), 2) == 1924.33
result = await Book.objects.avg(["year", "ranking"])
assert round(float(result.get("year")), 2) == 1924.33
assert result.get("ranking") == 3.0
try:
# cannot avg string column
await Book.objects.avg("title")
except ormar.QueryDefinitionError:
pass
result = await Author.objects.select_related("books").avg("books__year")
assert round(float(result), 2) == 1924.33
result = await Author.objects.select_related("books").avg(
["books__year", "books__ranking"]
)
assert round(float(result.get("books__year")), 2) == 1924.33
assert result.get("books__ranking") == 3.0
assert (
await Author.objects.select_related("books")
.filter(books__year__lt=1925)
.avg("books__year")
== 1921.5
)
```
## min
`min(columns) -> Any`
Returns min value of columns for rows matching the given criteria (applied with `filter` and `exclude` if set before).
You can pass one or many column names including related columns.
As of now each column passed is aggregated separately (so `sum(col1+col2)` is not possible,
you can have `sum(col1, col2)` and later add 2 returned sums in python)
If you aggregate on one column, the single value is directly returned as a result
If you aggregate on multiple columns a dictionary with column: result pairs is returned
```Python
--8<-- "../docs_src/aggregations/docs001.py"
```
A sample usage might look like following
```python
author = await Author(name="Author 1").save()
await Book(title="Book 1", year=1920, ranking=3, author=author).save()
await Book(title="Book 2", year=1930, ranking=1, author=author).save()
await Book(title="Book 3", year=1923, ranking=5, author=author).save()
assert await Book.objects.min("year") == 1920
result = await Book.objects.min(["year", "ranking"])
assert result == dict(year=1920, ranking=1)
assert await Book.objects.min("title") == "Book 1"
assert await Author.objects.select_related("books").min("books__year") == 1920
result = await Author.objects.select_related("books").min(
["books__year", "books__ranking"]
)
assert result == dict(books__year=1920, books__ranking=1)
assert (
await Author.objects.select_related("books")
.filter(books__year__gt=1925)
.min("books__year")
== 1930
)
```
## max
`max(columns) -> Any`
Returns max value of columns for rows matching the given criteria (applied with `filter` and `exclude` if set before).
Returns min value of columns for rows matching the given criteria (applied with `filter` and `exclude` if set before).
You can pass one or many column names including related columns.
As of now each column passed is aggregated separately (so `sum(col1+col2)` is not possible,
you can have `sum(col1, col2)` and later add 2 returned sums in python)
If you aggregate on one column, the single value is directly returned as a result
If you aggregate on multiple columns a dictionary with column: result pairs is returned
```Python
--8<-- "../docs_src/aggregations/docs001.py"
```
A sample usage might look like following
```python
author = await Author(name="Author 1").save()
await Book(title="Book 1", year=1920, ranking=3, author=author).save()
await Book(title="Book 2", year=1930, ranking=1, author=author).save()
await Book(title="Book 3", year=1923, ranking=5, author=author).save()
assert await Book.objects.max("year") == 1930
result = await Book.objects.max(["year", "ranking"])
assert result == dict(year=1930, ranking=5)
assert await Book.objects.max("title") == "Book 3"
assert await Author.objects.select_related("books").max("books__year") == 1930
result = await Author.objects.select_related("books").max(
["books__year", "books__ranking"]
)
assert result == dict(books__year=1930, books__ranking=5)
assert (
await Author.objects.select_related("books")
.filter(books__year__lt=1925)
.max("books__year")
== 1923
)
```
## QuerysetProxy methods
When access directly the related `ManyToMany` field as well as `ReverseForeignKey`
returns the list of related models.
But at the same time it exposes a subset of QuerySet API, so you can filter, create,
select related etc related models directly from parent model.
### count
Works exactly the same as [count](./#count) function above but allows you to select columns from related
objects from other side of the relation.
!!!tip
To read more about `QuerysetProxy` visit [querysetproxy][querysetproxy] section
### exists
Works exactly the same as [exists](./#exists) function above but allows you to select columns from related
objects from other side of the relation.
### sum
Works exactly the same as [sum](./#sum) function above but allows you to sum columns from related
objects from other side of the relation.
### avg
Works exactly the same as [avg](./#avg) function above but allows you to average columns from related
objects from other side of the relation.
### min
Works exactly the same as [min](./#min) function above but allows you to select minimum of columns from related
objects from other side of the relation.
### max
Works exactly the same as [max](./#max) function above but allows you to select maximum of columns from related
objects from other side of the relation.
!!!tip
To read more about `QuerysetProxy` visit [querysetproxy][querysetproxy] section
[querysetproxy]: ../relations/queryset-proxy.md